The present invention is an improvement of the invention of U.S. Pat. No. 5,261,818 (1993) to Shaw, entitled Multi-Fluted Dental Irrigation Drill, and U.S. Pat. No. 6,106,292 (2000) to the present inventive entity, entitled Dental Irrigation Drill with Internal Anti-Backwash Baffle.
The invention relates to dental drills and, more particularly, to so-called fluted irrigation spade drills employed in the creation of channels in the human jaw prior to the insertion of an implant of a post upon which a dental structure such as an abutment or bridge is to be placed. A difficulty in prior art dental drills of the above type is that, due to rotational eccentricity and flutter relative to the axis of rotation of the drill, a degree of trauma is imparted to the jawbone of the patient. Further, the dentist cannot effectively control pressure and depth of penetration of the drill where eccentricity or flutter exists in the drill action.
The present improvement of the above-referenced patent to Shaw entails changes in the external geometry thereof and, internally, provides to the irrigation channel thereof an anti-backwash baffle formed between opposing press-fittable complemental surfaces of a shank cutting portion of the drill. Accordingly, the present invention improves upon the invention of Shaw both in terms of cutting effect of external geometry and in terms of internal fluid flow characteristic. More particularly, the structure of the present invention employs a flat stub nose geometry, as opposed to complex distal end surfaces of the drill of Shaw and, additionally, provides an internal baffle or valve to create a fluid tight seal medially within the irrigation channel of the drill to prevent backwash into the shank portion thereof, a phenomenon which is undesirable in terms of both the aesthetics of implant dentistry and in terms of disrupting concentration of the dentist during implant procedures. These advantages are achieved while maintaining the positive associated with said reference to Shaw, namely, a superior implant cutting tool which facilitates a maximum of osseo-integratation of the implant within the implant site of the jawbone.
Other related art known to the within inventors includes U.S. Pat. No. 5,569,035 (1996) to Balfour et al; U.S. Pat. No. 5,791,902 (1998) to Lauks; and No. U.S. Pat. No. 5,839,897 to Borders.